Garden beet is the ancestor of fodder beets and sugar beets, but the origin of garden beet’s genetic potential to evolve novel beet types is debatable. In this study, we analyzed nuclear and mitochondrial DNAs in 47 garden beet accessions using DNA markers. Multiple analytical methods revealed a unified population structure with subpopulations evident in the European and Caucasian accessions. We diagnosed mitochondrial genome types (mitotypes) based on mitochondrial minisatellite loci in 541 plants from the 47 accessions, revealing a major mitotype and 11 minor mitotypes in garden beets from Europe and the Caucasus region that were also present in endemic leaf beets and wild beets. Our data indicate that European and Caucasian garden beets include genetically differentiated subpopulations. Provided that the occurrence of minor mitotypes is a vestige from crosses with leaf beets and wild beets, the notion that introgression contributed to increasing the genetic diversity in the garden beet gene pool is substantiated at the molecular level.

花园甜菜是饲料用甜菜和甜菜的祖先，但花园甜菜进化出新型甜菜类型的遗传潜力的起源是有争议的。在这项研究中，我们使用 DNA 标记分析了 47 个花园甜菜种质中的核和线粒体 DNA。多种分析方法揭示了统一的种群结构，在欧洲和高加索种质中具有明显的亚种群。我们根据来自 47 个种质的 541 株植物的线粒体小卫星位点诊断了线粒体基因组类型（mitotypes），揭示了来自欧洲和高加索地区的花园甜菜中的主要有丝分裂型和 11 种次要有丝分裂型，它们也存在于地方性甜菜和野生甜菜中。我们的数据表明欧洲和高加索花园甜菜包括基因分化的亚群。